WASHINGTON (Reuters) – The 2012 presidential race, now entering its most intense phase, has already set records for the number of ads and their negativity, according to experts.

Among the reasons: more money than ever to spend by a larger number of spenders, like “Super PACs,” which are outside groups formally unaffiliated with campaigns.

Put together, the Republican and Democratic presidential campaigns and about a dozen groups backstopping them have invested almost $600 million in advertising, heavily concentrated on just a handful of competitive states that hold the key to victory this year, including Iowa, Ohio, Colorado, Florida, Virginia, Nevada and, lately, Wisconsin.

The barrage is just getting started.

As of early September 2012, TV viewers in local markets had seen 1.3 million political ads, according to a September 13 article in Advertising Age magazine by Elizabeth Wilner, who tracks political ad spending at Kantar Media’s CMAG.

By her calculation, there could be another 2.3 million before the November 6 election.

Campaigns and backers of both President Barack Obama, a Democrat, and Mitt Romney, a Republican, are introducing close to a video a day — some for TV, some for the web. They are able to react almost instantly to the racing news cycle, and their ads reflect an overall feel of a contest marked by incessant attacks and few constructive policy proposals.

In the past two weeks alone, Obama and Romney campaigns each introduced at least a dozen new ads. By comparison, Ronald Reagan aired 27 ads in his entire 1984 campaign, according to John Geer, political science professor at Vanderbilt University and a top expert on negative advertising.

“If you talk about the TV era, since 1952 forward, I think 2012 will go down at this point in time as the most negative on the record,” Geer said.

“You’ve got an incumbent with a mixed record, you’ve got a challenger with a mixed record, the parties that are highly polarized, and you have a lot of money — the combination offers a perfect cocktail for negativity.”

The ads are not above getting personal. One Obama spot, defending his record on trade with China, asks: “How can Mitt Romney take on the cheaters, when he’s taking their side?”

In a Romney ad released last week, a woman welcomes her newborn daughter to the world, where her “share of Obama’s debt is over $50,000″ and women struggle with high rates of poverty and unemployment.

“We dislike candidates now,” said Michael Franz, who studies political advertising at Bowdoin College in Maine. Instead of being a “struggle of ideas,” he said, “elections are now about convincing people that the other guy is dangerous for America.”

Negativity in political ads is nothing new, as research continues to prove it does not deter voters and, Geer said, often yields more substantial ads that provide context or hold politicians accountable.

What’s fanning the flames this year is the amount of cash available, thanks in part to both campaigns foregoing public financing with its spending limits and unlimited spending by outside groups such as “super” political action committees or tax-exempt advocacy organizations.

It is the costliest campaign cycle in history, with presidential and congressional races widely forecast to attract some $6 billion in spending.

GOING FOR THE KILL

Academic Wesleyan Media Project, co-chaired by Franz, earlier this month reported that the 2012 campaign was more negative than the presidential contest of 2008 and that more ads were solely attack ads, those that mention only the opponent and not the candidate on whose behalf the ad aired.

Pro-Romney spots, fed by conservative Super PACs and non-profit groups, were “overwhelmingly negative,” according to the research. It found 72 percent of them focusing solely on Obama and 13 percent contrasting the two candidates.

With pro-Obama spots, 46 percent were pure attacks on Romney and a quarter offered a contrast.

Romney has honed in on Obama’s record on economic recovery, trying to link lagging job growth with anti-business attitudes, excessive regulation and a timid attitude toward China.

One recent ad campaign accused Obama of undermining the coal industry, important to the swing state of Ohio, for example.

American Crossroads, the Super PAC run by a veteran Republican operative Karl Rove, echoes the message in an ad.

“Obama has made a lot of bad decisions. He treats us like we are his enemy,” says Bill Schams, introduced in the Crossroads ad as running a business that’s been in the family since 1949.

The anti-Romney ads focus largely on his wealth and his background as a private equity executive, seeking to portray him as not caring about nor understanding ordinary people.

Many of Obama’s latest ads focus on the healthcare plan proposed by Romney’s vice presidential running mate, Paul Ryan, that would revamp the Medicare program for seniors.

Priorities USA Action, the Super PAC run by former Obama aides, is responsible for perhaps the most memorable ad of the race: the spot that insinuated that Bain Capital, the private equity firm Romney used to run, had something to do with the death of a woman from cancer.

The suggestion was based entirely on the fact that the woman’s husband, Joe Soptic, had lost his job at a steel plant closed by Bain five years before her death.

The power of negative ads was showcased in North Carolina earlier this year when Republican presidential hopeful Newt Gingrich won the state’s vote for his nomination after a multimillion-dollar ad campaign by the Super PAC backing him pounced against Romney.

Even more recently, Obama’s allies at Priorities USA took credit for some of Obama’s resurgence in polls after its string of anti-Bain ads.

Negative ads use “scare tactics,” said Michael O’Brien, vice president of broadcast sales at E.W. Scripps Company, “and it works. The people who are undecided are impacted by it.”